Seed planters, particularly row crop planters, often include several seed planting units transversely arranged relative to a travel direction of the planter. The seed planting units commonly include a pair of furrowing discs that create a furrow as they move across the ground. The seed planting units may also include a hopper for carrying seeds to be planted. The seeds may be selectively released from the hopper and passed through a seed tube extending down between or slightly behind the furrowing discs. As such, the seed in the seed tube may be passed to the furrow created in the ground by the furrowing discs. To better prepare the furrow for passage of the seed tube and placement of the seed, the planting unit may also include a leading device that extends into the furrow between or slightly behind the furrowing discs, but ahead of the seed tube. In some cases, fertilization tubing, for example metal tubing, may be provided that is connected to a source of liquid fertilizer or other liquid on the planting unit. The tubing may be attached to the leading device to place liquid starter fertilizer in the furrow ahead of the seed. Additionally, this allows for the liquid to be placed beneath the seed and not on top.
Problems with current systems can occur due to engagement of the fertilization tubing with the ground. In some cases, the unprotected tubing may be agitated due to dragging along the ground causing the released fertilizer to splatter. In other cases, while metal tubing may be provided, the fertilization tubing may experience wear as it passes through the furrow ultimately leading to a leak in the tubing. In both cases, the fertilizer may spray or splatter on components of the planter. For example, the fertilizer may splatter onto the furrowing discs causing it to be further spread onto other portions of the planter due to the spinning motion of the furrowing discs. The liquid splatter on the disc can also cause seeds to adhere thereto. In addition to wasting fertilizer, this splattering fertilizer can be corrosive to equipment requiring difficult cleaning or accelerated deterioration of equipment.